This invention relates to woodworking bench vises Woodworking benches are widely and typically used for supporting and, in many instances, temporarily fixing a workpiece in place on the bench while it is being worked. A variety of means for holding workpieces in temporarily fixed positions on or relative to woodworking benches have been utilized. Prominent among those means are vises in various configurations and locations on the bench, principally including front vises and end vises.
It is frequently desirable for either type of vise to be of substantial width, but it is difficult to obtain a satisfactory vise width greater than approximately twelve inches utilizing a single vise screw, even when multiple guide rods are employed. Accordingly, twin screws have been used in vises of substantially greater width and to realize other benefits associated with the use of twin screws. One such ability is the possibility of skewing the vise jaws relative to each other. While the ability to skew the vise jaws relative to each other (or to skew a movable jaw relative to the bench edge against which it closes) that is inherent in the use of two vise screws is often desirable, it is more frequently desirable that the two screws rotate in synchronism so that the front jaw will move in and out parallel to the rear one or, if a skewed position is needed, the relative skew will remain constant. Previous twin screw vises have achieved synchronized rotation by coupling the two screws with a chain, belt or similar means. Among other drawbacks, such twin screw vises have often been inconvenient to use and difficult to "recalibrate" after operating in a skewed configuration.